<!doctype html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>金字塔</title>
	<script type="text/javascript">
		var n=prompt("请输入行数","");
		for(var i=1;i<=n;i++){
			document.write('<p style="text-align:center;margin:0px;">')
			for(var j=0;j<2*i-1;j++){
				document.write("*"+"&nbsp;"+"&nbsp;");
			}
			document.write("</p>");
			// document.write("<br>");			
		}
	</script>
</head>
<body>
	
</body>
</html>